fyi for cracking with bkcrack, if the file in the zip is compressed (as all the XY zips are) your input plaintext will also need to be compressed too
it can be difficult since any byte changes before the offset you want to use in bkcrack will throw off the compression (assuming you're even using the exact same deflate algo that GF did back in 2013)
really you'd be better off bruteforcing any compressed ZIPs like the XY ones
t.
https://github.com/kimci86/bkcrack/blob/master/example/tutorial.md#the-not-so-easy-way-deflated-file 